Bryce Harper suffers mild left hamstring strain, to be evaluated further Friday

Bryce Harper left tonight's 5-3 loss to the Rays in the six inning with what Nationals manager Matt Williams called a "mild left hamstring strain." That seems to be promising news considering the tense moments following Harper's injury.

The Rays trailed 3-2 with Logan Forsythe on second and Steven Souza Jr. on first with one out in the top of the sixth when Asdrubal Cabrera singled on sharp groundball into right field. Rays third base coach Charlie Montoyo threw up the stop sign when Forsythe rounded the bag, but Harper still came up firing to the plate. He appeared to slip on the wet field, with his legs buckling on the release of the ball, and the errant throw sailed wildly up the third base line, ending up out of play and allowing both runs to score. Not only did the Nats lose the lead, but Harper was sprawled out on the turf in right field in obvious pain.

Anthony Rendon and Ian Desmond quickly rushed to tend to Harper, followed by Williams and head athletic trainer Lee Kuntz. Kuntz spent a few minutes examining Harper's left leg before Harper was able to get to his feet. He limped off the field on his own power.

Harper felt the wet grass played a major part in the injury after the game was delayed for 17 minutes in between the fourth inning with a passing heavy rain shower.

"I came up throwing, and it was really slippery out there with the rain, and my right knee gave out and then I put all my pressure on my left knee and got my hamstring, lower hamstring, and the knee a little bit," Harper said. "But, I mean, it didn't feel very good. I was in pretty good pain. A little scared at the same time because I could feel a little bit more on the lower half of it. But I'll see how I am tomorrow and go from there."

Harper obviously was relieved that it didn't appear to be as bad as it initially seemed.

"Absolutely," he said. "With the way it felt ... you know, I've had problems with my left knee before. I've had surgery on it. So it was definitely really scary. It didn't feel all that great when I was laying there. So pretty scary. But talked to the doc a little bit, get what he thought and then see how it felt. Very happy with what it feels like."

Harper had surgery on his left knee in November 2013 to remove a bursa sac. That was a lingering issue that resulted from Harper crashing into the Dodger Stadium right field wall while trying to make a catch in May 2013.

Last Saturday, Harper took a fastball on the inside of the same knee that forced him to sit out the following day and appear as the designated hitter in Monday's game.

The Nationals slugger indicated that he has never experienced hamstring injuries in the past. He said he doesn't feel an MRI will be needed.

"I'm just gonna see how it feels tomorrow, you know, be smart about it, of course," Harper said. "It's still early. So just try to be as smart as I can. I want to be in there, but if it don't feel right tomorrow, then maybe taking that day off might help me a little bit. We'll see how I feel."

Before the injury, Harper was 1-for-3 with an RBI. He drilled a line drive off Rays starter Chris Archer's left foot in the first that caromed into left field, allowing Denard Span to score easily.

Harper continues to drive the Nats' offense, batting .344 with 22 homers and 52 RBIs.